/*
 *    Copyright 2006-2020 the original author or authors.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.mybatis.generator.plugins;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.mybatis.generator.api.FullyQualifiedTable;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.IntrospectedTable.TargetRuntime;
import org.mybatis.generator.api.PluginAdapter;
import org.mybatis.generator.api.dom.java.FullyQualifiedJavaType;
import org.mybatis.generator.api.dom.java.Interface;
import org.mybatis.generator.api.dom.java.Method;
import org.mybatis.generator.api.dom.java.Parameter;
import org.mybatis.generator.api.dom.xml.Attribute;
import org.mybatis.generator.api.dom.xml.Document;
import org.mybatis.generator.api.dom.xml.XmlElement;
import org.mybatis.generator.internal.util.messages.Messages;

/**
 * This plugin will add selectByExample methods that include rowBounds
 * parameters to the generated mapper interface. This plugin is only valid for
 * MyBatis3.
 *
 * @author Jeff Butler
 */
public class RowBoundsPlugin extends PluginAdapter {

	private final FullyQualifiedJavaType rowBounds = new FullyQualifiedJavaType("org.apache.ibatis.session.RowBounds"); //$NON-NLS-1$
	private final Map<FullyQualifiedTable, List<XmlElement>> elementsToAdd = new HashMap<>();

	@Override
	public boolean validate(List<String> warnings) {
		if ("MyBatis3DynamicSql".equalsIgnoreCase(context.getTargetRuntime())) { //$NON-NLS-1$
			warnings.add(Messages.getString("Warning.30")); //$NON-NLS-1$
			return false;
		}
		return true;
	}

	@Override
	public boolean clientSelectByExampleWithBLOBsMethodGenerated(Method method, Interface interfaze,
			IntrospectedTable introspectedTable) {
		if (introspectedTable.getTargetRuntime() == TargetRuntime.MYBATIS3) {
			copyAndAddMethod(method, interfaze);
		}
		return true;
	}

	@Override
	public boolean clientSelectByExampleWithoutBLOBsMethodGenerated(Method method, Interface interfaze,
			IntrospectedTable introspectedTable) {
		if (introspectedTable.getTargetRuntime() == TargetRuntime.MYBATIS3) {
			copyAndAddMethod(method, interfaze);
		}
		return true;
	}

	@Override
	public boolean sqlMapSelectByExampleWithoutBLOBsElementGenerated(XmlElement element,
			IntrospectedTable introspectedTable) {
		if (introspectedTable.getTargetRuntime() == TargetRuntime.MYBATIS3) {
			copyAndSaveElement(element, introspectedTable.getFullyQualifiedTable());
		}
		return true;
	}

	@Override
	public boolean sqlMapSelectByExampleWithBLOBsElementGenerated(XmlElement element,
			IntrospectedTable introspectedTable) {
		if (introspectedTable.getTargetRuntime() == TargetRuntime.MYBATIS3) {
			copyAndSaveElement(element, introspectedTable.getFullyQualifiedTable());
		}
		return true;
	}

	/**
	 * We'll override this method and add any new elements generated by previous
	 * calls.
	 */
	@Override
	public boolean sqlMapDocumentGenerated(Document document, IntrospectedTable introspectedTable) {
		List<XmlElement> elements = elementsToAdd.get(introspectedTable.getFullyQualifiedTable());
		if (elements != null) {
			for (XmlElement element : elements) {
				document.getRootElement().addElement(element);
			}
		}

		return true;
	}

	/**
	 * Use the method copy constructor to create a new method, then add the
	 * rowBounds parameter.
	 *
	 * @param method    the method
	 * @param interfaze the interface
	 */
	private void copyAndAddMethod(Method method, Interface interfaze) {
		Method newMethod = new Method(method);
		newMethod.setName(method.getName() + "WithRowbounds"); //$NON-NLS-1$
		newMethod.addParameter(new Parameter(rowBounds, "rowBounds")); //$NON-NLS-1$
		interfaze.addMethod(newMethod);
		interfaze.addImportedType(rowBounds);
	}

	/**
	 * Use the method copy constructor to create a new element.
	 *
	 * @param element the base element
	 * @param fqt     the fully qualified type
	 */
	private void copyAndSaveElement(XmlElement element, FullyQualifiedTable fqt) {
		XmlElement newElement = new XmlElement(element);

		// remove old id attribute and add a new one with the new name
		Iterator<Attribute> iterator = newElement.getAttributes().iterator();
		while (iterator.hasNext()) {
			Attribute attribute = iterator.next();
			if ("id".equals(attribute.getName())) { //$NON-NLS-1$
				iterator.remove();
				Attribute newAttribute = new Attribute("id", attribute.getValue() + "WithRowbounds"); //$NON-NLS-1$ //$NON-NLS-2$
				newElement.addAttribute(newAttribute);
				break;
			}
		}

		// save the new element locally. We'll add it to the document
		// later
		List<XmlElement> elements = elementsToAdd.computeIfAbsent(fqt, k -> new ArrayList<>());
		elements.add(newElement);
	}
}
